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US 8,044,436 B2Granted
Avalanche photodiode having controlled breakdown voltage
AssigneePrinceton Lightwave, Inc.
InventorMark Allen Itzler
Life of this patent
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Abstract
Avalanche photodiodes and methods for forming them are disclosed. The breakdown voltage of an avalanche photodiode is controlled through the inclusion of a diffusion sink that is formed at the same time as the device region of the photodiode. The device region and diffusion sink are formed by diffusing a dopant into a semiconductor to form a p-n junction in the device region. The dopant is diffused through a first diffusion window to form the device region and a second diffusion window to form the diffusion sink. The depth of the p-n junction is based on an attribute of the second diffusion window.
Claims19
An apparatus comprising a first APD, wherein the first APD comprises:
- a first diffusion region that is doped with a first dopant, wherein the first diffusion region comprises a first device region and a first diffusion sink, and wherein the first device region and the first diffusion sink are non-contiguous, and further wherein the diffusion depth in the first device region is based on a first attribute of the first diffusion sink;
- wherein the first attribute is based on a pre-established relationship between diffusion depth in a first portion of a second diffusion region comprising the first portion and a second portion when the second portion is characterized by the first attribute.
An apparatus comprising:
- a semiconductor layer comprising a first semiconductor;
- a first device region of a first APD, wherein the first device region is formed in the semiconductor layer, and wherein the first device region is doped with a first dopant;
- a second device region of a second APD, wherein the second device region is formed in the semiconductor layer, and wherein the second device region is doped with the first dopant;
- and
- a first diffusion sink formed in the semiconductor layer, wherein the first diffusion sink is doped with the first dopant;
- wherein the first device region, second device region, and first diffusion sink collectively define at least a portion of a first diffusion region, and wherein the first device region and the first diffusion sink are separated by a minimum separation distance that is substantially equal to a separation distance, d, and wherein the second device region and the first diffusion sink are separated by a minimum separation distance that is substantially equal to the separation distance, d, and further wherein the diffusion depth of the first dopant in the first device region and the diffusion depth of the first dopant in the second device region are substantially equal and based on the separation distance, d;
- and
- wherein the separation distance, d, is based on a pre-established relationship between diffusion depth in a first portion of a second diffusion region and the separation distance between the first portion and a second portion of the second diffusion region.
5 more elements
An apparatus comprising:
- a substrate comprising a semiconductor layer comprising a first semiconductor;
- a first device region of a first APD, wherein the first device region is formed in the semiconductor layer, and wherein the first device region is doped with a first dopant;
- a second device region of a second APD, wherein the second device region is formed in the semiconductor layer, and wherein the second device region is doped with the first dopant;
- a first diffusion sink formed in the semiconductor layer, wherein the first diffusion sink is doped with the first dopant;
- and
- a second diffusion sink formed in the semiconductor layer, wherein the second diffusion sink is doped with the first dopant;
- wherein the first device region, second device region, first diffusion sink, and second diffusion sink collectively define at least a portion of a first diffusion region, and wherein the first device region and the first diffusion sink are separated by a minimum separation distance that is substantially equal to a first separation distance, d1, and wherein the second device region and the second diffusion sink are separated by a minimum separation distance that is substantially equal to a second separation distance, d2;
- wherein d1 is based on (1) a pre-established relationship between diffusion depth in a first portion of a second diffusion region and the separation distance between the first portion and a second portion of the second diffusion region and (2) the location of the first APD on the substrate;
- and
- wherein d2 is based on (1) the pre-established relationship and (2) the location of the second APD on the substrate.
7 more elements
Dependencies are inferred from the claim text.